Power take-off



July l0, 19451. H. R. VAN vLEcK POWER TAKE-OFF Y Filed. June 25, 1941 -2 sheets-sheet 1 ATTORNEYS July 10, 1945. H. R. VAN vLEcK POWER TAKE-OFF 2 Sheets-Sheet 2 Filed June 25, 1941 Patented July 10, 1945 estaria POWER. TAKE-OFF Horace Russ Vain Vleck, Upper Montclair, N. J.

Appiicauen June z5, 1941, serial 399,625

2 claims. (ci. 1st-t3) lhis invention relates to power take-etiv mechanisms and more particularly to a novel mech- `anism oi this type which may be operated from a vehicle engine, orthe like, to drive a generator, a pump or other device at a speed in excess of the engine speed and with a power output which may be varied without changing the speed. The new mechanism is simple and compact in construction land may be operated easily and with safety by reason of its inclusion of automatic means for disconnecting the vehicle driving maintaining the take-oil mechanism inoperative,

but which positively prevents simultaneous opera ation of the take-ou mechanism and the propel-- ling device. In accordance with my invention, the connection between the engine` and the pro-s pelling device includes a drive shaft having two independent sections, one of which .ls a driving section rotatable by the engine through a suitable' connection and the other of which is a driven section connected to the propelling device. The power take-oil mechanism includes a driven ele nient with relation 'to which the drive shaft is rotatable, and selector means tor connecting the driving section of the shaft to either the driven element of the taire-oil or the driven. section oi' the shaft. take-off is concentric te the vehicle'drive shaft, and the selector means includes a clutch member rotatable with the driving sectionof the shaft and engageable selectively with enacting clutch members on the drivenelement of the tmc-oil and the driven section of the shaft, respectively. The driven clement ci the take-oid maybe conf Preferably, the driven 'element oi thel dentally with possible resulting injury t0 the equipment. The connection between the engine and the take-oil is the usual power transmission of the vehicle, and, therefore, is suiliciently strong and does not require additional parts. When the take-off is used on trucks or other vehicles having a variable speed transmission betweenl the engine and the drive shaft, the take-off may be driven at diilerent speeds by simply shifting the gears of the transmission4 in the usual manner.

Another feature oi the invention resides in the provision of a novel power takeuofi in which the speed ratio between the driving section of the vehicle drive shaft and theengine is increased when the selector means is moved to disconnect the driven section f the shaft and connect the driven element of the take-oir. In one form of my invention, a step-upV gear box is disposed in the connection between the engine and the driving section of the shaft and is provided with a control member having a low speed and a high speed position. When the selector means connects the driving section of the shaft to the driven section and the propelling device, the `control member of the step-up box is in its low speed position. However, when the selector means is shifted to connect the driven element of the taireo to the drivingsection of the shait, the control member is shifted to itshigh speed position, whereby the talrewoii is operated Aat high speed while the engine isidling. If desired, the selector means of the take-off and. the control member of the step-up gear bon may be connected to gether so that the control member is shifted lautomatically when the selector means nested to a device to be driven, such as a een erator or a pump.

With this construction, the driving section oi the vehicle shaft is adapted to drive either the propelling device or the taire-off mechanism but not both. Accordingly, accidental movement of the vehicle by the engine during operation oi 'the take-oir is impossible. This is of particular ad Vantage in the use of the take-off on a truck, for

example, to drive auxiliary equipment when the` struction it is impossible while 'the vehicle is in transit to drive the auxiliary equipment accioperated..

in the use or the power take-aofi of my iiivenM tion on the usual ground vehicles having a vartable speed transmission, the power delivered by the taheisoii may be increased without changing the speed or operation ci the tare-,cfr by simply moving thefgcar shift of thetransmisslon to a lower speed position and increasing the engine speed sufdcientlyto counteract the'reduction in the speed ratio. Conversely, the power delivered bythe take-ofi may be decreased without charian ing its speed, by moving the gear shift to a higher speed position. and reducing the engine speed.

Iihese and. other-ieatures of the invention may be better understood by reference to the accompanying drawings, in which Y Fig. 1 is a plan view of a truck chassis on which' is mountedoneforrn of the invention for driving an auxiliary generator; e

Fig. 2 is a top view partlyin section showing the generator of Figc 1 with the drive shaft exy Fig. 4 is a sectional view on the line 4 4 in clutch (not shown) to a variable speed transmission I3. The transmission I3 may be of the usual type having a gear shift lever I4 movable selectively from a neutral position to reverse, low speed, second speed or high speed positions. The driven element of the transmission is coupled t a shaft I5 extending into a step-up gear box IS containing gears (not shown) which may be ar ranged to drive at either low speed or high speed depending upon the position of a control lever I'I on the outside of the box. Coupled to the driven element in the gear box I6 is a propeller shaft or drive shaft including two independent sections 23 and 2l. The drive shaft 20, 2I extends through an auxiliary generator 23 mounted on the vehicle frame, the rear section 2| of the shaft being connected through a differential 24 and a.

' the vehicle and is used to supply current to electrical equipment, such as an electric motor for operating a pump to deliver the contents of a tank on the chassis.

The housing of generator 23 is provided with an extension 28 which encloses the adjacent ends of thc drive shaft sections 2D and 2I, as shown in Fig. .2. At its rear end, the front or driving section 2Il'of the shaft is formed with a reduced extension 29 received in a socket 30 on the adjecent end of the rear or driven section 2l. A thrust plate 3l is disposed betweenv the end of extension 29 and the closed end of socket 30, and the extension 23 is supported in the socket by roller bearings 32. The rear section 2I of the shaft is supported by roller bearings 33 mounted in a suitable raceway 34 in the housing exten;- sion 28.

On the front section 2U of the drive shaft directly in front of socket 30 is a double-acting vclutch member 35splined to the section 20 by keys 31. The front face of the clutch member is provided with clutch teeth 38, and the rear face is provided with clutch teeth 39 engageable with coacting clutch teeth 40 on al circumferential flange 4I at the adjacent end of shaft section 2|. The clutch teeth 38 are engageable with co acting clutch teeth 43 on a circumferential flange 44 at the rear end of a sleeve 45 extending axially through the generator and concentric to shaft section 23. At its opposite ends, the sleeve 45 is.

supported by roller bearings 46 mounted in suit able racewaysin the generator, `and preferably a thrust bearing (not shown) is provided to take up the forward thrust of sleeve 45 when its` 43 on the rear section of the drive shaft or the clutch teeth 43 on sleeve 45. Any desired means may be employed to shift the clutch member from one position to the other. As shown in Fig. 1, I provide for this purpose a lever 50 pivotally mounted at il on the extension n or the generator housing and connected intermediate its ends through a slot 52 in the housing 'to a yoke 53, the arms of which are engaged in a circumferential groove in the clutch member 33. If desired, the free end of lever 50 may be connected by a link 54 tol the control lever Il of the step-up gear box I6, and the lever 53 may be provided with an operative connection to a handle in the truck cab (not shown).

In operation, when the vehicle is in transit the clutch member 3B engages clutch teeth 40 on the rear section 2l ot the drive shaft,\so that the engine drives the rear wheels 2B through the transmission I3, step-up gear box I6, drive shaft 20, 2I, differential 24 and rear axle 25. In this position of clutch member 36, the control lever I1 of the step-up gear box is in its low speed position which preferably gives a one-to-one speed ratio between shafts I5 and 20. With the clutch member 3B in this position, it is impossible for the engine to drive the generator 23 because the clutch teeth 33 are disengaged and spaced from the clutch teeth 43 on the sleeve 45 which drives the rotatable windings of the generator. When the vehicle has reached its destination and it is desired to operate the gen erator 23, the lever 50 is shifted to disengage the clutch member 36 from teeth 4I) l:and engage it with teeth 43 on sleeve 45. At the same time, the control lever II of the step-up gear box is shifted to its high speed position which causes shaft section 20 to rotate at a higher speed than the shaft I5. The clutch between the engine and transmission I3 is then engaged with the gear shift lever I4 in one of itsfoperating positions, such as the high speed position, whereby the engine drives the generator 23 through transmission I3, shaft l5, step-up gear box I6, front sec tion 2D of the drive shaft, clutch 36 and sleeve 45. It will be apparent that with the. clutch member 33 in this position it is impossible for the engine to drive the rear wheels 23 because clutch teeth 33 are disengaged and spaced from the durch teeth tu en the drive shaft section zi. Because of the step-up gear box I6 the generator 23 is driven at a considerably higher speed than the speed of the engine I2, and, therefore, the engine may be idled while the generator is operating. g

' When it is desired to increase the power supplied to the generator Without increasing the speed of the generator, the gear shift lever I4 is shifted from the high speed position to one of the lower speed positions and the engine l2 is accelerated sufficiently to counteract the decreased speed ratio of the driving connection betweenthe engine and shaft I5. Thus, assuming that the transmission I3 has three different speeds, power may be delivered to the generator 23 In any one of three different amounts without changing the speed of the generator. This is of particular advantage when the generator is used for energizing various electrical units and the demand on the generator is different for each unit. When the demand is heavy, the transmission is shifted to the low speed position and the engine is voperated at a relatively high speed, while with a lower current demand the transmistion may be shifted to a higher speed position and the engine decelerated. Accordingly. with the new take-off mechanism a generator of xelastant speed even though the demand on it varies over avwide range.

The generator 23, which is preferably of the dust-proof and llame-proof type, not only serves as a source of power from the take-oi! mechanism but also contributes to the support of the drive shaft 20, 2|. Also, it houses the clutch between rthe two sections of the drive shaft, although it will be understood that any other suitable casing may be employed for this purpose. While I have shown the generator 23 disposed intermediate the ends of the drive shaft 20, 2|, it may be arranged further toward :the front of the vehicle so that the front section 26 of the drive shaft extends directly into the generator and is not exposed. The rear section 2| may then be encased in the usual torque tube extending between the differential 24 and the generator. Since the generator is mounted at the same height as the drive shaft 26, 2|, there is ample road clearance. y

In the construction shown in Figs. 3 and 4, the drive shaft comprises two independent sections a and 2|a arranged end to end, the section 20a having a reduced portion 29a received in a. socket 30a at the adjacent end of the rear section 2|a. A Ithrust plate Sla is disposed between the end of the socket 60a and the rear end of the reduced portion 29a. and the reduced portion is supported in the socket by roller bearings 32a. The rear section 2|a of the drive shaft may be provided with additional supporting means in the form of radial bearings 33a. A clutch member 36a is splined to the front section of the drive shaft by keys 31a land is provided on its opposite faces with clutch teeth 38a and 39a. respectively. The teeth 39a are engageable with clutch teeth Illa on a circumferential flange Ila at the adjacent end of rthe rear section 2|a of the shaft.

The teeth 38a on the clutch member are engageable with clutch teeth 43a on the hub of a bevel gear 56 mounted loosely on the drive shaft section 20a. Extending forwardly from the gear 56 is an integral sleeve portion 51 on the end of which a plate 58 is threaded, the plate being engaged by .thrust bearings 59 which take up the thrust incident to engagement of the clutch member with teeth 43a. In front of the thrust bearing' 69, the shaft section 26a may be supported by radial bearings 60.

Meshing with the bevel gear 66 are smaller bevel gears 62, 63 and 64 mounted on shafts 465, 66 and 61, respectively, Journaled on the frame of the vehicle. These shafts may be connected to power ope'rated devices, such as pumps, gen

into engagement with teeth 40a, the rear wheels or other propelling means of thel vehicle are driven through the rear section 2|a of the drive shaft, and the driving gear 56 of the power takeoff is inoperative. However, when the clutch member 36a is moved into engagement with teeth 43a, the driving gear 56 of the Itake-off is driven directly from the front section 20a of the drive shaft, while the rear section 2|a and the propelling means are inoperative. Because of the bevel gears 56, o2, 63 and 64, the drive from the shaft section 20a to the auxiliary powerdriven devices is substantially noiseless.

It will be apparent that the power take-off of my invention is eincient and extremely flexible in that it may be operated at different power output values without changing its speed, by manipulation of the usual throttle and gear shift lever of the vehicle, or `it may be operated at different speeds. The speed step-up mechanism between the engine and the unit driven by the power take-off permits operation of .the unit at relatively high speed with the engine idling, whereby lthe operation is at low cost.

I claim:

l. In a power take-off device, the improvement comprising a housing, a generator mounted in the housing, a drive-shaft extending into one end of the housing, a sleeve in operative connecerators, air compressors, etc. While I have shown v .three bevel gears driven by thev gear 66, it will be understood .that any desired number of gears may be used to provide multiple power take-offs from the drive shaft 26a, 2|a. Also, while the power take-off shafts 66, and 61 are shown extending at right angles to the main drive shaft, they may be made lto extend at any desired angle relative thereto by employing gears 62, 63 and 64 of the proper bevel angle. Since the gears 62, 53 and 64 are considerably smaller in diameter than the driving gear 56, the power take-off shafts 65, 66 and 61 are operated at much higher speed than the drive shaft 20a, 2|a, and it is therefore unnecessary to use a step-up gear bo such as that shown at I6 in Fig. 1.

The operation of the take-oir mechanism shown in Figs. 3 and 4 is generally similar to that shown in Fig. 1 and will be readily understood. When the clutch member 36a is moved tion with the generator, the sleeve extending` axially through the generator and concentric to the drive-shaft, the drive-shaft being rotatable relative to the sleeve, a roller-bearing assembly mounted between the drive-shaft and lthe sleeve, arroller-bearing assembly 4mounted between the sleeve and a journal forming an integral portion of the housing, a circumferential power take-off gear integrally mounted on the inner end of 4the sleeve, a driven-shaft extending into the opposite end of the housing in axial alignment with the drive-shaft, a roller-bearing assembly mounted between the driven-shaft and a journal forming an integral portion of the housing, the inner end of the driven-shaft .terminating in a hollow socket and :the inner end of the drive-shaft fitting into the hollow socket, a roller-bearing assembly mounted between the inner end of the driveshaft and the hollow socket of the driven-shaft, a circumferential propelling gear integrally mounted on the inner end of the driven-shaft, a clutch slidably mounted on and rotatable with the drive-shaft intermediate the hollow socket of the driven-shaft and the power take-off gear, clutch teeth circumferentially spaced on one side of the clutch adapted operatively to mesh with the teeth of the power take-olf gear mountedvon the sleeve, clutch teeth circumferentially spaced on the other side of the clutch adapted operatively to mesh with the teeth of the propelling gear mounted on .the driven-shaft, a shifter associated with the clutch adapted selectively to slide the clutch laterally into and out of operative engagement with the power .take-olf gear and into and out of operative engagement with the propelling gear so that simultaneous operation of the generator and .the propelling gear is prevented.

2. A power take-off device according to the preceding claim, in which the shifter is operatively connectable with means for increasing the speed of the drive-shaft when the clutch is placed in engagement with the power take-off gear, so that the rotation of the sleeve may be speeded when it is desired to operate the generator.

HORACE RUSS VAN VLECK. 

